http://download.neurosky.com/docs/papers/bcq/Klimesch_1999_EEG_alpha_and_theta_oscillations_reflect_cognitive_and_memory_performance.pdf

EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis

羟氨苄青霉素引起大疱性类天疱疮样疹

Judith Jacobi, PharmD, FCCM, BCPS; Gilles L. Fraser, PharmD, FCCM; Douglas B. Coursin, MD; Richard R. Riker, MD; Dorrie Fontaine, RN, DNSc, FAAN; Eric T. Wittbrodt, PharmD; Donald B. Chalfin, MD, MS, FCCM; Michael F. Masica, MD, MPH; H. Scott Bjerke, MD; William M. Coplin, MD; David W. Crippen, MD, FCCM; Barry D. Fuchs, MD; Ruth M. Kelleher, RN; Paul E. Marik, MDBCh, FCCM; Stanley A. Nasraway, Jr, MD, FCCM; Michael J. Murray, MD, PhD, FCCM; William T. Peruzzi, MD, FCCM; Philip D. Lumb, MB, BS, FCCM. Developed through the Task Force of the American College of Critical Care Medicine (ACCM) of the Society of Critical Care Medicine (SCCM), in collaboration with the American Society of Health-System Pharmacists (ASHP), and in alliance with the American College of Chest Physicians; and approved by the Board of Regents of ACCM and the Council of SCCM and the ASHP Board of Directors

/pdf/clinical-practice-guidelines-for-the-sustained-use-of-550x8gqibj.pdf

Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult.

http://www.unicog.org/publications/DehaeneChangeux_ReviewConsciousness_Neuron2011.pdf

Experimental and Theoretical Approaches to Conscious Processing

Background:The bispectral index (BIS), a value derived from the electroencephalograph (EEG), has been proposed as a measure of anesthetic effect. To establish its utility for this purpose, it is important to determine the relation among BIS, measured drug concentration, and increasing levels of seda

Bispectral Analysis Measures Sedation and Memory Effects of Propofol, Midazolam, Isoflurane, and Alfentanil in Healthy Volunteers

Background:The authors evaluated the effects of midazolam, propofol, thiopental, and fentanyl on volunteer participants' memory for words and pictures at equisedative concentrations.Methods:Sixty-seven healthy volunteers were randomized to receive intravenous infusions of midazolam (n = 11), propofo

The comparative amnestic effects of midazolam, propofol, thiopental, and fentanyl at equisedative concentrations.

Clinical and Echocardiographic Correlates of Symptomatic Tachydysrhythmias After Noncardiac Thoracic Surgery

BACKGROUND Changes in regional cerebral blood flow (rCBF) determined with H2(15)O positron emission tomographic imaging can identify neural circuits affected by centrally acting drugs. METHODS Fourteen volunteers received one of two midazolam infusions adjusted according to electroencephalographic response. Low or high midazolam effects were identified using post-hoc spectral analysis of the electroencephalographic response obtained during positron emission tomographic imaging based on the absence or presence of 14-Hz spindle activity. The absolute change in global CBF was calculated, and relative changes in rCBF were determined using statistical parametric mapping with localization to standard stereotactic coordinates. RESULTS The low-effect group received 7.5 +/- 1.7 mg midazolam (serum concentrations, 74 +/- 24 ng/ml), and the high-effect group received 9.7 +/- 1.3 mg midazolam (serum concentrations, 129 +/- 48 ng/ml). Midazolam decreased global CBF by 12% from 39.2 +/- 4.1 to 34.4 +/- 6.1 ml x 100 g(-1) x min(-1) (P < 0.02 at a partial pressure of carbon dioxide of 40 mmHg). The rCBF changes in the low-effect group were a subset of the high-effect group. Decreased rCBF (P < 0.001) occurred in the insula, the cingulate gyrus, multiple areas in the prefrontal cortex, the thalamus, and parietal and temporal association areas. Asymmetric changes occurred, particularly in the low-effect group, and were more significant in the left frontal cortex and thalamus and the right insula. Relative rCBF was increased in the occipital areas. CONCLUSION Midazolam causes dose-related changes in rCBF in brain regions associated with the normal functioning of arousal, attention, and memory.

Midazolam Changes Cerebral Blood Flow in Discrete Brain Regions: An H2-15O Positron Emission Tomography Study

The electroencephalographic effects of two intravenous sedative/hypnotic drugs, propofol and thiopental, were studied at three stable blood concentrations in 52 normal healthy volunteers. The higher concentration resulted in unresponsiveness (lack of response to auditory/tactile stimuli) in all subjects. This report describes the strong frontal-central rhythms apparent in this state using a quantitative description of oscillatory systems underlying the rhythm. These rhythms occur when sedative drug concentrations are greater than those producing the well-described increase in broadband β-power associated with many sedative drugs. Propofol induces rhythms in the α-range, while thiopental produces rhythms in the β-range. Quasistationary for a period of about 1 h, these rhythms exceed the baseline α-rhythm in power. By their resonant nature, these propofol-induced rhythms are analogous to ‘the classic α-rhythm’, but quantitative characteristics of the underlying oscillatory systems are different. Baseline properties of the oscillatory system underlying the initial resting α-rhythm recover completely as drug concentration decays to negligible values.

Propofol-Induced Alpha Rhythm

Propofol has a greater amnesic effect than thiopental. In this study we tested whether different brain regions were affected by propofol and thiopental at similar drug effects. Changes in regional cerebral blood flow (rCBF) were identified by using SPM99 analysis of images obtained with positron emission tomography with (15)O water. Ten right-handed male volunteers (age, 35 +/- 10 yr; weight, 74.1 +/- 7.5 kg; mean +/- sd) were randomized to receive thiopental (n = 4) or propofol (n = 6) to target sedative and hypnotic concentrations with bispectral index (BIS) monitoring. Four positron emission tomography images were obtained during various tasks at baseline and with sedative and hypnotic effects. Two participants receiving propofol were unresponsive at sedative concentrations and were not included in the final analyses. Median serum concentrations were 1.2 and 2.7 microg/mL for sedative and hypnotic propofol effects, respectively. Similarly, thiopental concentrations were 4.8 and 10.6 microg/mL. BIS decreased similarly in both groups. The pattern of rCBF change was markedly different for propofol and thiopental. Propofol decreased rCBF in the anterior (right-sided during sedation) brain regions, whereas thiopental decreased rCBF primarily in the cerebellar and posterior brain regions. At similar levels of drug effect, propofol and thiopental affect different regions of the brain. These differences may help to identify the loci of action for the nonsedative effects of propofol, such as amnesia.

Ruth A. Reinsel

Papers

The comparative amnestic effects of midazolam, propofol, thiopental, and fentanyl at equisedative concentrations.

Clinical and Echocardiographic Correlates of Symptomatic Tachydysrhythmias After Noncardiac Thoracic Surgery

Midazolam Changes Cerebral Blood Flow in Discrete Brain Regions: An H2-15O Positron Emission Tomography Study

Propofol-Induced Alpha Rhythm

Thiopental and propofol affect different regions of the brain at similar pharmacologic effects.